题解

#include<bits/stdc++.h>
using namespace std;
int n,a[1001],b[1001],r;

void dfs(int k){
	for (int i = 1; i <= n; i++){
		if (b[i] == 0){
			b[i] = 1;
			a[k] = i;
			if (k == n){
				for (int j = 1; j <= n; j++){
					cout << a[j] << ' ';
				}
				cout << endl;
			} else {
				dfs(k + 1);
			}
			b[i] = 0;
		}
	}
}

int main(){
	cin >> n;
	dfs(1);
	
	return 0;
}